Sorry for the delay – I’ve been away for a couple of weeks. It’s based on a combination of things, including UK sales, how much I’ve been listening to it recently, and various other factors. It’s completely spurious, but it makes me happy.

I did try to get a few different bloggers together to compile it at one point, but there wasn’t a lot of interest at the time, and I don’t think I’d have time right now. Actually, I thought there was a post that explained all of this somewhere, but I can’t find it right now…